package com.yc.d0312;

import com.google.gson.Gson;
import com.yc.util.DBHelper;

import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.annotation.*;
import java.io.IOException;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

@WebServlet(name = "QueryNewsServlet", value = "/QueryNewsServlet.s")
public class QueryNewsServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        final String pageSize = request.getParameter("pageSize");
        final String currentPage = request.getParameter("currentPage");
        int size = Integer.valueOf(pageSize);
        int page=Integer.valueOf(currentPage);
        int begin = size * (page-1);
        //说明：该案例中的SQL直接写在Servlet中，项目中不允许
        String sql = "select * from hyfc_news";
        //查询当前页的数据
        final List<Map<String, Object>> data=
                DBHelper.selectListMap(sql + " limit ?, ?",begin, size);
        //查询总行数
        final long total = DBHelper.count(sql);

        Map<String, Object> result = new HashMap<>();
        result.put("data",data);
        result.put("total",total);
        final  String json = new Gson().toJson(result);
        response.getWriter().append(json);


    }

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

    }
}
